1. Field of the Invention
The present invention relates to a testing device control system for controlling testing devices such as automatic product testing equipment installed in production lines of factories.
2. Description of the Related Art
Today, almost all production lines of factories utilize automatic testing devices for automatically testing products such as communication equipment produced by the production lines. However, few production lines employ measures to control possible failures of the testing devices themselves and their attachments such as pallets that carry products. In case a testing device develops a failure, the product that the device is testing can be regarded as defective even though the product itself is in fact acceptable. Where the product testing is carried out unattended during the night or during other non-business hours, decisions cannot be made on whether the apparent failure detected is a product defect or a device failure and no follow-up countermeasures can be taken because no competent personnel are present at site. As a result, testing becomes inefficient. Thus the need is recognized for a testing device control system capable of automatically controlling testing device failures.
FIG. 1 is a schematic view of a typical prior art testing line for testing products such as communication equipment. In FIG. 1, a conveyor 1 rotating in circular fashion, i.e., in the arrowed direction Y1 and Y2, carries pallets 2 on which products 3 are mounted. As shown in FIG. 2, a schematic side view of the pallet and its connecting device, the product 3 is first placed on the pallet 2. Then a connector, not shown, of the product 3 is connected to a connector, not shown, at the tip of a cable 5 coupled to a connector 4 of the pallet 2.
Along the conveyor 1 are a plurality of automatic testing devices 7a through 7e. These automatic testing devices are equipped respectively with automatic connecting devices 6a through 6c each automatically attaching to the connector 4 of the pallet 2. It is cables 8 that connect the automatic connecting devices 6a through 6c respectively to the automatic testing devices 7a through 7c. The automatic connecting devices 6a through 6c electrically attach and detach the products 3 to and from the automatic testing devices 7a through 7c by means of pallets 2, the products 3 being carried along by the conveyor 1. The attaching and detaching of products 3 is accomplished as shown in FIG. 2. That is, a pin 10 of a connector 9 for each of the automatic connecting devices 6a through 6c is moved bidirectionally in an arrowed direction Y3 so as to connect with the connector 4 of the pallet 2.
As depicted in FIG. 3, a block diagram of a typical prior art automatic testing device control system, the automatic testing devices 7a through 7c are each composed of a disc unit 21 that stores various testing items and a computer 20 that controls the disc unit 21. Each computer 20 is connected to a host computer 19. The results of the testing of diverse testing items done by the automatic testing devices 7a through 7c are gathered by the host computer 19 and stored into a main disc unit 22. The gathered information is output to a printer 23 as needed.
Each of the automatic testing devices 7a through 7c has its computer 20 read from the main disc unit 22 a testing item file containing the necessary items to be tested by each device so that these marked items will be tested separately by the devices assigned thereto. Under this automatic testing device control system, the automatic testing devices 7a through 7c test or measure each product conveyed by the conveyor 1 for various electric characteristics defined by the testing items. The results are collected by the host computer 19 for each product tested or measured. Control information on the tested results, product failure information, control information on the completed test results and other relevant information are output by the printer 23.
The above-described prior art automatic testing device control system has one major disadvantage. That is, the system can find a product 3 to be defective even though its electric characteristics are normal, in case of a poor or severed connection involving any of the connectors 4 or cables 5 of the pallets 2 or the connectors 9 or cables 8 of the automatic connecting devices 6a through 6c, or in case of a failure involving any of the automatic testing devices 7a through 7c themselves.
The judgment calling a given product 3 a failure as a result of a faulty testing device or a malfunctioning pallet can only be corrected by competent personnel poring over the failure information output by the printer 23 about that product. This means that judgments on product failure may not be always correct and that countermeasures to correct the failure may not be implemented timely. Where testing is performed unattended during the night or during other non-business hours, the failure in a testing device or in its attachments cannot be corrected on the spot.